Dominant Connexin Mutations and Hearing Loss

显性连接蛋白突变与听力损失

• 批准号: 7035819
• 负责人: SABRINA W YUM
• 金额: $ 18.99万
• 依托单位: DREXEL UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-04-12 至 2009-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7035819
• 关键词: Golgi apparatus; HeLa cells; autosomal dominant trait; cochlea; deafness; electron microscopy; endoplasmic reticulum; gap junctions; gene environment interaction; gene mutation; genetically modified animals; hearing disorders; hearing tests; immunocytochemistry; immunofluorescence technique; laboratory mouse; lysosomes; membrane channels; northern blottings; phenotype; potassium ion; regulatory gene; terminal nick end labeling; transfection; western blottings

DESCRIPTION (provided by applicant): Three genes (GJB2, GJB3, GJB6) encode for gap junction proteins (connexin 26 (Cx26), (Cx30) and (Cx31) respectively), are found to cause dominant and/or recessive hearing loss. How these mutations cause hearing loss remains unknown. While both recessive and dominant mutants have impaired function, the dominant mutants might have additional dominant negative effects on the wild type counterparts or even trans-dominant inhibition effects on each other, as Cx26, Cx30 and Cx31 are all expressed in the cochlea. The loss of gap junction coupling in cochlear cells may affect the homeostasis of potassium ions in the inner ear and cause hearing impairment. To test these hypotheses, cellular and animal models will be generated to analyze the effects of dominant GJB2/Cx26, GJB6/Cx30, and GJB3/Cx31 mutations, with the following three Specific Aims: 1) to determine the effects of dominant GJB2/Cx26, GJB6/Cx30, and GJB3/Cx31 mutations on the assembly, trafficking and function of their cognate mutant protein in gap junction-deficient HeLa cells; 2) to determine the effects of dominant GJB2/Cx26, GJB6/Cx30, and GJB3/Cx31 mutations on HeLa cells that express wild-type human Cx26, Cx30 and Cx31; 3) to generate and analyze animal models of selected dominant GJB2/Cx26 mutations, by expressing these mutants in the mesenchymal cells of the cochlea. The trafficking and functional results of the cellular and animal models will elucidate the fundamental cellular and molecular mechanism of dominant GJB2/Cx26, GJB6/Cx30, and GJB3/Cx31 mutations, and the animal models of selected mutations will serve as a fundamental resource for further study of the causes and treatments of these inherited causes of deafness. The principle investigator proposed this five year supervised research experience and didactic training to serve as a transitional period from a clinician to a clinician scientist. Dr. Scherer, who has performed similar analyses on the effects of GJB1/Cx32 mutations, will mentor her scientific development, along with Dr. Crenshaw, an established investigator in neurobiology and auditory biology. The work will be supported by the collaboration of Dr. Saunders, an established investigator in the neurobiology and physiology of hearing. An external advisory committee of highly regarded expert in connexin and auditory biology will provide additional support and advice. My goal is to become a well trained independent investigator in biomedicine. The excellent academic environment and the tremendous resource at the University of Pennsylvania, as well as the commitment of her institute will maximize her potential to succeed.

描述(申请人提供)：三个基因(GJB2，GJB3，GJB6)编码缝隙连接蛋白(分别为Cx26，Cx30和Cx31)，被发现导致显性和/或隐性听力损失。这些突变是如何导致听力损失的尚不清楚。由于Cx26、Cx30和Cx31均在耳蜗组织中表达，隐性突变体和显性突变体都有功能受损，但显性突变体可能对野生型突变体产生额外的显性负效应，甚至对彼此产生反显性抑制效应。耳蜗细胞间隙连接偶联的丧失可能影响内耳内钾离子的动态平衡，导致听力障碍。为了验证这些假设，将建立细胞和动物模型来分析显性GJB2/Cx26、GJB6/Cx30和GJB3/Cx31突变的影响，目的如下：1)确定显性GJB2/Cx26、GJB6/Cx30和GJB3/Cx31突变对缝隙连接缺陷HeLa细胞中其同源突变蛋白的组装、运输和功能的影响；2)确定显性GJB2/Cx26、GJB6/Cx30和GJB3/Cx31突变对表达野生型人Cx26、Cx30和Cx31的HeLa细胞的影响；3)通过在耳蜗间充质细胞中表达GJB2/Cx26突变，建立和分析GJB2/Cx26突变的动物模型。细胞和动物模型的转运和功能结果将阐明显性GJB2/Cx26、GJB6/Cx30和GJB3/Cx31突变的基本细胞和分子机制，而所选突变的动物模型将为进一步研究这些遗传性耳聋的病因和治疗提供基础资源。首席研究员提出了这五年的监督研究经验和教学培训，作为从临床医生到临床医生科学家的过渡期。谢勒博士曾对GJB1/Cx32突变的影响进行过类似的分析，她将与克伦肖博士一起指导她的科学发展，克伦肖博士是神经生物学和听觉生物学领域的知名研究员。这项工作将得到桑德斯博士的合作支持，桑德斯博士是听觉神经生物学和生理学领域的知名研究员。一个由备受尊敬的连接蛋白和听觉生物学专家组成的外部咨询委员会将提供额外的支持和建议。我的目标是成为一名训练有素的生物医学独立研究员。宾夕法尼亚大学优良的学术环境和巨大的资源，以及她所在学院的承诺，将使她获得成功的潜力最大化。